Amid mounting opposition from the B.C. government, environmental groups and protesters, not to mention skittish investors, Kinder Morgan halted all non-essential spending on its $7.4-billion plan to double an existing pipeline between Edmonton and Burnaby, B.C., and gave Ottawa until the end of May to broker some calm.

Morneau says investors need certainty in order to back a project that the government has repeatedly insisted is in the national interest.